FMVSS 206: Door locks and door retention explained.

What FMVSS 206 says it is for

The eCFR heads this section "Standard No. 206; Door locks and door retention components." Under 49 CFR part 571, the Federal Motor Vehicle Safety Standards are the numbered standards that set safety performance requirements for motor vehicles and equipment. The text below is quoted from 571.206 as current through October 29, 2026.

This standard specifies requirements for vehicle door locks and door retention components, including latches, hinges, and other supporting means, to minimize the likelihood of occupants being ejected from a vehicle as a result of impact.

What it applies to

The application section of the standard says:

This standard applies to passenger cars, multipurpose passenger vehicles, trucks designed to carry at least one person, and buses with a gross vehicle weight rating (GVWR) of 4,536 kg or less.

Applicability is decided by the text of the standard as written, including any exclusions it lists, and by the date-specific rules in it. This page does not decide whether a particular vehicle or item is covered.

How the standard is organized

The eCFR text of 571.206 has these top-level sections:

• S1: Scope and Purpose
• S2: Application
• S3: Definitions
• S4: Requirements
• S5: Test Procedures

In all, the text has 40 numbered headings. Use the finder above to search them; for example, a search for "test" lists the headings that mention tests.

Key requirements, quoted from the text

These are excerpts from the requirements sections of 571.206, in the order the standard presents them. Long paragraphs are shortened where marked; the eCFR has the complete text, tables and figures, which this page omits.

S4 Requirements. The requirements apply to all side and back doors, that lead directly into a compartment that contains one or more seating accommodations and the associated door components, except for those on folding doors, roll-up doors, detachable doors, bus doors used only for emergency egress purposes and labeled accordingly and on bus doors to accommodate a permanently attached wheelchair lift system that when the device is in the retracted position, the lift platform retracts to a vertical orientation parallel to and in close proximity with the interior surface of the lift door and in that position, the platform completely covers the doorway opening, has fixed attachments to the vehicle and provides a barricade to the doorway. [excerpt continues in the eCFR]

S4.1.1 Primary and Auxiliary Door Latch Systems. Each hinged door system shall be equipped with at least one primary door latch system. By the time a vehicle is certified a manufacturer shall designate the door latch system(s) that is the “primary door latch system(s).” Upon certification, a manufacturer may not thereafter alter the designation of a primary door latch system. Each manufacturer shall, upon request from the National Highway Traffic Safety Administration, provide information regarding such designation.

S4.2.1 Latch System. Each sliding door system shall be equipped with either: (a) At least one primary door latch system, or (b) A door latch system with a fully latched position and a door closure warning system. The door closure warning system shall be located where it can be clearly seen by the driver. Upon certification a manufacturer may not thereafter alter the designation of a primary latch. Each manufacturer shall, upon request from the National Highway Traffic Safety Administration, provide information regarding such designation.

S4.3 Door Locks. Each door shall be equipped with at least one locking device which, when engaged, shall prevent operation of the exterior door handle or other exterior latch release control and which has an operating means and a lock release/engagement device located within the interior of the vehicle.

S5.3 Sliding Side Doors. Compliance with S4.3 shall be demonstrated by applying an outward transverse load of 8,900 Newtons (2,000 pounds) to the load-bearing members at the opposite edges of the door (17,800 Newtons (4,000 pounds) total). The demonstration may be performed either in the vehicle or with the door retention components in a bench test fixture.

Defined terms

The standard defines 24 terms in its definitions section. Definitions are quoted from the eCFR.

• Auxiliary Door Latch is a latch equipped with a fully latched position, with or without a secondary latched position, and fitted to a door or door system equipped with a primary door latch system.
• Auxiliary Door Latch System consists of door latches and strikers other than those associated with the primary door latch system.
• Back Door is a door or door system on the back end of a motor vehicle through which passengers can enter or depart the vehicle or cargo can be loaded or unloaded. It does not include:
• Body Member is that portion of the hinge normally affixed to the body structure.
• Door Closure Warning System is a system that will activate a visual signal when a door latch system is not in its fully latched position and the vehicle ignition is activated.
• Door Hinge System is one or more hinges used to support a door.
• Door Latch System consists of latches and strikers installed on a door system.
• Door Member is that portion of the hinge normally affixed to the door structure and constituting the swinging member.
• Door System is the door, latch, striker, hinges, sliding track combinations and other door retention components on a door and its surrounding doorframe. The door system of a double door includes both doors.
• Double Door is a system of two doors where the front door or wing door opens first and connects to the rear door or bolted door, which opens second.
• Folding Door is a movable barrier, which will close off an entranceway to a bus, multipurpose passenger vehicle or truck, consisting of two or more hinge panels that swing, slide, or rotate; does not have a striker and latch assembly.
• Fork-bolt is the part of the latch that engages and retains the striker when in a latched position.
• Fork-bolt Opening Direction is the direction opposite to that in which the striker enters the latch to engage the fork-bolt.
• Fully Latched Position is the coupling condition of the latch that retains the door in a completely closed position.
• Hinge is a device system used to position the door relative to the body structure and control the path of the door swing for passenger ingress and egress.
• Hinge Pin is that portion of the hinge normally interconnecting the body and door members and establishing the swing axis.
• Latch is a device employed to maintain the door in a closed position relative to the vehicle body with provisions for deliberate release (or operation).
• Primary Door Latch is a latch equipped with both a fully latched position and a secondary latched position and is designated as a “primary door latch” by the manufacturer.
• Primary Door Latch System consists of a primary door latch(s) and a striker(s).
• Secondary Latched Position refers to the coupling condition of the latch that retains the door in a partially closed position.
• Side Front Door is a door that, in a side view, has 50 percent or more of its opening area forward of the rearmost point on the driver's seat back, when the seat back is adjusted to its most vertical and rearward position. [continues in the eCFR]
• Side Rear Door is a door that, in a side view, has 50 percent or more of its opening area to the rear of the rearmost point on the driver's seat back, when the driver's seat is adjusted to its most vertical and rearward position. [continues in the eCFR]
• Striker is a device with which the latch engages to maintain the door in the fully latched or secondary latched position.
• Trunk Lid is a movable body panel that provides access from outside the vehicle to a space wholly partitioned from the occupant compartment by a permanently attached partition or fixed or fold-down seat back.

Limits of this page

This page quotes the text of 49 CFR 571.206 as published in the eCFR, current through October 29, 2026. It omits tables, figures, cross-referenced test procedures in other parts, and the preambles and rulemaking history that explain the rule. It does not tell you whether a given vehicle, part or product complies, how to run a test, or what a manufacturer must certify. Compliance questions go to the manufacturer's engineers, qualified counsel or NHTSA. The eCFR is an editorial compilation, not the official legal edition of the Federal Register.

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 571.206, Standard No. 206; Door locks and door retention components. (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR part 571, Federal Motor Vehicle Safety Standards (current through October 29, 2026) (read November 2, 2026)